Mozilla Firefox 1.5 Beta 1
New Firefox for testing purposes, with improvements on tab browsing, faster browser navigation, better usability and more. Keep in mind this version is not compatible with most of the existing extensions.

Mozilla Thunderbird 1.5 Beta 1
The new beta testing version for the great email client. New features include spell check as you type, podcast and RSS enhancements, better usability and server side spam filtering support. This maybe easier to test – like me I am happy to use Thunderbird without any extensions.

Firefox Preloader
“Firefox Preloader is a utility that is designed to load parts of Mozilla Firefox into memory before it is used to improve the its startup time.”